Strength evaluation of a steam distribution device in the Ignalina NPP accident localisation system

The Ignalina NPP has a pressure suppression type of confinement, which is referred to as the accident localization system (ALS). The ALS prevents the release of the radioactive material from the NPP to the environment during a loss-of-coolant accident (LOCA). Ten water pools are located in the two ALS towers (five pools in each tower), which separate the dry well from the wet well. These water pools condense the accident-generated steam and prevent high overpressures in the compartments.The steam distribution device (SDD), with the vertical vent pipes (nozzles) that are inserted under the water of the condensing pools, connects the dry well and the wet well. In case of an accident, these components must be capable of withstanding the dynamic loads generated by a LOCA for successful pressure suppression function.This paper presents the transient analysis of the SDD and their connections to the vertical steam corridors following a LOCA. A thermo-hydraulic analysis of the SDD was performed using the state-of-the-art COCOSYS code to determine pressure and temperature histories resulting from a LOCA. The finite element code NEPTUNE was used to evaluate the structural integrity of the SDD and its supporting reinforced concrete wall. Results show that, although portions of the SDD undergo plastic response and the outside surface of the vertical steam corridor reinforced concrete wall cracks, the structural integrity of the SDD and wall are maintained during a LOCA.     

Structure and mechanical properties of powder materials of the system Ti - Al - Si

The structure and mechanical properties of cast and powder materials of the Ti - Al - Si system are studied. It is established that eutectic compositions of this system display superior strength properties to existing heat-resistant titanium alloys. Translated from Poroshkovaya Metallurgiya, Nos. 5–6(413), pp. 108–116, May–June, 2000.     

Factors influencing the selection of university majors varying in mathematical content.

53 male and 58 female undergraduates completed an arithmetic test and a questionnaire on their mathematics background, perceived skill, interest, and affect toward math. Most women avoided majors that required even moderate amounts of math, even though they were as skilled at arithmetic as males and had taken equivalent amounts of math in high school. Ss who were anxious about math avoided majors that had moderate or high math requirements. Ss who were less skilled at arithmetic chose majors with fewer math requirements. Because gender and negative affect toward math contributed independently to choice of major, interventions to combat math anxiety could be valuable for both males and females. (French abstract) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The immunocorrective potentials of an antistaphylococcal immunosorbent in extracting staphylotoxin

The immunocorrective effect of antistaphylococcal adsorbent prepared on the basis of silochrome, a silica matrix, has been revealed in experiments on peripheral blood lymphocytes obtained from 18 donors. The expression of receptors on human immunoregulating cells has been suppressed by the addition of staphylotoxin at a toxic concentration into the system. The experiments have shown that immunosorption is capable of extracting the toxin from the solution to a considerable degree, thus preventing the suppression of the receptor apparatus of immunoregulating lymphocytes. Staphylotoxin has been found capable of forming complexes with plasma ingredients, which increases the adsorption capacity of the immunosorbent.     

Photoelectrochemical properties of bismuth oxyhalide films

The photoelectrochemical (PEC) properties of bismuth oxyhalide (BiOCl, BiOBr, and BiOI) electrodes prepared by anodic oxidation of bismuth films on a platinum substrate have been studied. In acidified potassium halide solutions, these electrodes have been found to exhibit the PEC properties characteristic of p-type semiconductors. The efficiency of the PEC process appreciably decreases in the series BiOCl> BiOBr> BiOI. Effective protectors of the BiOHal electrode photodecomposition are dissolved oxygen and hydroquinone/quinone redox pair. The spectral sensitization of BiOHal electrodes can be carried out by different dyes, the quantum efficiency of the sensitized process being relatively high (3–7%) in a number of cases. The ways of increasing the stability of sensitized PEC process on BiOHal electrodes are considered.     

Structure and Mechanical Properties of Thick Metal Condensates Strengthened with Various Dispersed Particles. I. Strengthening Mechanism of Dispersion-Strengthened Metals

Powder Metallurgy and Metal Ceramics - Following the experimental data in Part I of this article, the present paper considers existing strengthening mechanisms of dispersion-strengthened alloys,...     

Magnetic Testing of Stressed State of Hydrotested Gas-Separator Wall

The stressed state of a hydrotested gas separator has been studied by magnetoelastic demagnetization. Correlation dependences are obtained between the level of magnetoelastic demagnetization of a complex-loaded gas-separator wall and the magnitude of hoop, meridian, and equivalent stresses it experiences. The magnetoelastic demagnetization of a residually magnetized test-object wall, loaded with internal pressure, was estimated from the change in the strength of its magnetic stray field measured along the normal (H_n) and tangent (H_τ) to the surface. It has been established that the growth of mechanical stresses in the separator wall to half the value of the yield strength of steel it is made of causes a noticeable irreversible decrease in the normal (H_n) and tangential (H_τ) components of the strength of its magnetic stray field in the residually magnetized area. It is shown that the method of magnetoelastic demagnetization has the highest sensitivity to mechanical stresses and is easiest to implement and most prompt compared with coercimetry and tensometry.